Hello @Henk Ve ,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
I understand that you are receiving HTTP error 413 when uploading files larger than 4 GB in your Application gateway WAF v2 SKU.
Azure Application gateway V2 has a maximum file upload limit of 4 GB for both Standard and WAF SKU (when you are using the new WAF engine with CRS 3.2 or newer). So, it doesn't matter if you are using WAF or not, the maximum limit for file upload remains at 4 GB as of today.
However, the upload size limits are STILL ENFORCED even if you disable the body inspection or disable OWASP WAF Rules (200002,200003,200004) completely or configure WAF in prevention mode as mentioned a bit later in the same documentation.
The section of the documentation that you are referring to here is for "Request body inspection".
The default value for request body size is 128 KB. But for CRS 3.2 (on the WAF_v2 SKU) and newer, you can set a 2 MB request body size limit.
And if the request body inspection is turned off, then maximum request body size field isn't applicable and can't be set. Same goes for max file upload limit field.
The above section talks about the behavior of WAF inspecting the request body depending on the mode of the WAF.
But the file upload limit remains the same which is 4 GB, and this is a hard limit. You cannot upload files larger than 4 GB as of today.
If you wish you may upvote the feedback in the below forum requesting this feature. All the feedback you share in these forums will be monitored and reviewed by the Microsoft engineering teams responsible for building Azure.
Azure WAF Product Group team recommends looking into chunking file uploads to exceed the 4GB limit.
Kindly let us know if the above helps or you need further assistance on this issue.
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